1. Field of the Invention
The present invention relates to a pallet for supporting an article, which can store and convey the article while supporting a predetermined weight of the article thereon.
2. Related Background Art
In the past, a pallet comprising a plate member and prismatic leg members fixed to an undersurface of the plate member has been used as a pallet for supporting and conveying an article. Both plate member and leg members were made of wood, and, accordingly, such conventional pallet was heavy and was not suitable to convey small and/or light-weighted articles. Further, as disclosed in the Japanese Utility Model Publication No. 48-694, a pallet comprising top and bottom main wall plates and a plurality of spaced cylindrical spacers fixedly arranged between the wall plates has been proposed. In addition, a pallet wherein such spacers are made of foam material has also been known. While such pallet comprising the wall plates and spacers had good resistance to pressure and/or load of the article supported thereon since the spacers were formed in the cylindrical configuration, adhesion strength between the top and bottom wall plates and the spacers was relatively weak because adhesion area between the wall plates and the spacers was small, and, thus, there arose a problem that the spacers were detached from the wall plates when the pallet had been used for a long time.
Regarding the leg members, the construction and/or material thereof have been devised or improved in various ways. For example, the Japanese Utility Model Publication Nos. 52-22756 and 58-45227 disclose a technique for increasing the stiffness of the leg members. However, in both cases, such improvements in the pallet made the construction of the pallet complicated, with the result that the pallet became heavy and expensive.
The pallet comprising a plate member and prismatic leg members fixed to an undersurface of the plate member is also disclosed in U.S. Pat. Nos. 2.996,276, 3,911,834, 3,952,672, 4,714,026.
The conventional wooden pallet has now been used widely since it has good resistance to load and has an adequate application condition. However, the price of wooden material has been increasing, and thus, the wooden pallet has become extremely expensive. Further, since the weight of the pallet itself is included in the transport weight determining the cost of transport of the articles, the reduction in the weight of the pallet itself leads to the reduction in the cost of transport directly. Accordingly, the reduction of the weight of the pallet is required.
Particularly, in case of exportation of the articles with the pallets by ship, the wooden pallets must sometimes be fumigated for the purpose of moth proofing according to the regulation of an importing country; this is an obstacle to the reduction in cost of the pallet. Further, in general, the pallets used in the exportation are scrapped in an importing country. The scrapping cost, which is cheaper than the recovery or returning cost, is not negligible. Accordingly, the reduction of such scrapping cost is also of concern.
In conclusion, as mentioned above, the conventional wooden pallets could not achieve the reduction of cost thereof adequately, and thus, are not economical.
Further, it is preferable to manufacture the pallet by paper material having various merits. However, if each of the leg members of the pallet is made of cylindrical paper material (cylindrical paper pipe), although adequate physical strength for usage of the pallet can be obtained, there is a problem in the connection or adhesion between the cylindrical paper pipes and the plate member of the pallet.
This is to say, in order to connect or fix the cylindrical paper pipes (leg members) to the plate member, an adhesive or fastener members such as staples can be used. However, when the adhesive is used, adequate adhesion strength cannot be obtained since the contacting area between the plate member and the cylindrical paper pipe is relatively small; on the other hand, when the fastener members are used, the fixing strength between the plate member and the cylindrical paper pipe is not sufficiently large.